The major goal of this project is to study the chemical properties and subcellular distribution of non-neural proteolipid apoproteins. When analyzed by polyacrylamide gel electrophoresis in 8 M urea-sodium dodecyl sulfate mixtures, all apoprotein samples prepared from heart, kidney, and liver tissues were found to contain a major 30,000 dalton protein and several other lower molecular weight proteins in lesser amounts. The specific goals of this project are: (1) to purify the most abundant heart apoprotein (30,000 daltons) and low molecular weight (less than 10,000 daltons) heart apoproteins by gel filtration chromatography and by preparative polyacrylamide gel electrophoresis; (2) to establish any chemical similarities between each purified apoprotein by determination of the amino acid composition, N- and C-terminal amino acid residues and by comparing of peptide maps (3) to determine the primary acid sequence of the most abundant heart apoprotein. Attempts will be made to prepare peptide fragments by enzymatic or chemical cleavage techniques. The amino acid sequence of purified peptides will be determined by the Edman degradative procedure, and by end group analysis; (4) to establish the nature of the fatty acid linkage to the apoprotein and to locate their precise site(s) of attachment to the polypeptide chain. The fatty acids will be released from the apoprotein by mild alkali treatment and characterized as the methylester by gas-liquid chromatography; (5) to determine the subcellular distribution of non-neural apoproteins with special emphasis on the mitochondrial membrane; (6) finally the project will be expanded to examine proteolipids from other non-neural sources. When the results of this study of the non-neural proteolipids are compared with the known properties of brain proteolipids, it may be possible to assign a common structural role for this class of hydrophobic proteins in many biologically diverse cell membranes.